The ________ are collectively called the calyx.

a. sepals

b. petals

c. tepals

d. stamens

The flower is the reproductive part of the plant body. The four whorl components are the Calyx, Corolla, Androecium and Gynoecium.

• The calyx and corolla are non-essential components of the flower.
• Androecium and gynoecium are two essential parts of the flower.
• The androecium is the male reproductive part of the flower.
• The female reproductive part of the flower called the gynoecium.

• The petals are collectively known as the Corolla. Petals are brightly coloured to attract insects for pollination. They're designed to aid pollination and thus increase the flower's chances of reproduction.
• Tepals are formed when the calyx and corolla are fused together and are indistinguishable from one another.
• Stamens are the male reproductive part of the flower. A stamen is made up of an anther and a filament.

Sepals are collectively called the calyx. Sepals, which are green leaf-like appendages, surround the closed bud. It protects the flower during the bud stage. It can also perform photosynthesis.

As a result, the proper response is (a).